Trosper Tire Company has decided to hire a new mechanic to handle all tire changes for customers ordering new tires. Two mechanics are available for the job. One mechanic has limited experience and can be hired for $7 per hour. It is expected that this mechanic can service an average of three customers per hour. A mechanic with several years of experience is also being considered for the job. This mechanic can service an average of four customers per hour, but must be paid $10 per hour. Assume that customers arrive at the Trosper garage at the rate of two per hour.

a. Compute waiting-line operating characteristics for each mechanic.

b. If the company assigns a customer-waiting cost of $15 per hour, which mechanic provides the lower operating cost?